Blelham Tarn Water Body

Moderate ecological status

Attributes

  • Water Body IDGB31229270
  • Water Body TypeLake
  • Hydromorphological designationnot designated artificial or heavily modified
  • NGRNY3667100495
  • Catchment area424.75 ha
  • Surface area0.106 km2
  • Altitude47 m
  • Mean depth6.79 m
  • Surveillance Water BodyNo
  • Surface area10.572 ha

Classifications

Classification Item2019
EcologicalModerate
Biological quality elementsGood
Macrophytes and Phytobenthos CombinedGood
Macrophytes Sub ElementGood
PhytoplanktonGood
Physico-chemical quality elementsModerate
SalinityHigh
Total NitrogenGood
Total PhosphorusModerate
Hydromorphological Supporting ElementsSupports good
Hydrological RegimeHigh
MorphologySupports good
Supporting elements (Surface Water)Moderate
Expert JudgementModerate
Specific pollutantsHigh
CopperHigh
ChemicalFail
Priority hazardous substancesFail
Benzo(a)pyreneGood
Dioxins and dioxin-like compoundsGood
Heptachlor and cis-Heptachlor epoxideGood
Hexabromocyclododecane (HBCDD)Good
HexachlorobenzeneGood
HexachlorobutadieneGood
Mercury and Its CompoundsFail
Perfluorooctane sulphonate (PFOS)Good
Polybrominated diphenyl ethers (PBDE)Fail
Priority substancesGood
FluorantheneGood
Other PollutantsDoes not require assessment

Why do all water bodies have a chemical status of fail?

Investigations into classification status

No data to show

Reasons for not achieving good (RNAG) and reasons for deterioration (RFD)

All reasons (RFDs and RNAGs) attributed to the classification elements in this water body.

Reason TypeSWMIActivityCategoryClassification ElementMore information
RNAGPoint sourceSewage discharge (continuous)Water IndustryMacrophytes and Phytobenthos CombinedDetails
RNAGmeasures delivered to address reason, awaiting recoveryNot applicableNo sector responsibleMercury and Its CompoundsDetails
RNAGDiffuse sourcePoor nutrient managementAgriculture and rural land managementMacrophytes and Phytobenthos CombinedDetails
RNAGmeasures delivered to address reason, awaiting recoveryNot applicableNo sector responsiblePolybrominated diphenyl ethers (PBDE)Details
RNAGPoint sourceSewage discharge (continuous)Water IndustryTotal PhosphorusDetails

Reasons for not achieving good status by business sector

The issues preventing waters reaching good status and the sectors identified as contributing to them. The numbers in the table are individual counts of the reasons for not achieving good status with a confidence status of 'confirmed' and 'probable', where the latest classification is less than good status. There may be more than one reason in a single water body. Note, table does not include reasons for deterioration.

Significant water management issuePhysical modificationsPollution from waste waterPollution from towns, cities and transportChanges to the natural flow and level of waterInvasive non-native speciesPollution from rural areasPollution from abandoned mines
Agriculture and rural land management0000000
Industry0000000
Mining and quarrying0000000
Navigation0000000
Urban and transport0000000
Water Industry0100000
Local & central government0000000
Domestic general public0000000
Recreation0000000
Waste treatment and disposal0000000
Other0000000
No sector responsible0000000
Sector under investigation0000000
Total0100000

Objectives

Classification ItemStatusYearReasons
EcologicalGood2027 - Low confidenceDisproportionately expensive: Disproportionate burdens;
Natural conditions: Ecological recovery time
Biological quality elementsGood2021Disproportionately expensive: Disproportionate burdens
Macrophytes and Phytobenthos CombinedGood2021Disproportionately expensive: Disproportionate burdens
PhytoplanktonGood2015
Physico-chemical quality elementsGood2027 - Low confidenceDisproportionately expensive: Disproportionate burdens;
Natural conditions: Ecological recovery time
Dissolved oxygenGood2027 - Low confidenceDisproportionately expensive: Disproportionate burdens;
Natural conditions: Ecological recovery time
SalinityGood2015
Total NitrogenGood2015
Total PhosphorusGood2015
Hydromorphological Supporting ElementsSupports good2015
Hydrological RegimeSupports good2015
Supporting elements (Surface Water)Good2027 - Low confidenceDisproportionately expensive: Disproportionate burdens;
Natural conditions: Ecological recovery time
Expert JudgementGood2027 - Low confidenceDisproportionately expensive: Disproportionate burdens;
Natural conditions: Ecological recovery time
Specific pollutantsHigh2015
CopperHigh2015
ChemicalGood2063Natural conditions: Chemical status recovery time
Priority hazardous substancesGood2063Natural conditions: Chemical status recovery time
Benzo(a)pyreneGood2015
Dioxins and dioxin-like compoundsGood2015
Heptachlor and cis-Heptachlor epoxideGood2015
Hexabromocyclododecane (HBCDD)Good2015
HexachlorobenzeneGood2015
HexachlorobutadieneGood2015
Mercury and Its CompoundsGood2040Natural conditions: Chemical status recovery time
Perfluorooctane sulphonate (PFOS)Good2015
Polybrominated diphenyl ethers (PBDE)Good2063Natural conditions: Chemical status recovery time
Priority substancesGood2015
FluorantheneGood2015
Other PollutantsDoes not require assessment2015

Protected areas

No data to show

Monitoring sites which have been used to classify this water body

Shows which sites were used for classification for which years within each cycle.

Monitoring SiteCycle 1Cycle 2Cycle 3
BLELHAM TARN 880161572012, 2013, 20142019, 2015, 2013, 2016, 20142019
162025 1620252009, 2013, 2014, 20122016, 2019, 2015, 2014, 20132019
BLELHAM BECK U/S LOW WRAY FARM 880045362015, 2016
155152 1551522016, 20192019

Upstream water bodies

    Downstream water bodies